MC68HC12 Datasheet, PDF (410/478 Pages) Motorola, Inc – The MC68HC912DT128A microcontroller unit (MCU) is a 16-bit device composed of standard on-chip peripherals including a 16-bit central processing unit

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R/W — Read/Write Flag
0 = Write
1 = Read
TTAGO — Trace, Tag, Go Field
Table 20-5. TTAGO Decoding
TTAGO Value
00
01
10
11
Instruction
—
GO
TRACE1
TAGGO
REGN — Register/Next Field
Indicates which register is being affected by a command. In the case of
a READ_NEXT or WRITE_NEXT command, index register X is pre-
incriminated by 2 and the word pointed to by X is then read or written.
Table 20-6. REGN Decoding
REGN Value
000
001
010
011
100
101
110
111
Instruction
—
—
READ/WRITE NEXT
PC
D
X
Y
SP
Technical Data
410
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MC68HC912DT128A — Rev 4.0
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